Constrained space cameras have been designed for use in a variety of different environments.
U.S. Pat. No. 4,272,781, for example, describes a camera equipped with rollers mounted to the assembly's outer housing, so that the assembly can be rolled under objects and maneuvered on the ground in areas having low overhead clearance. Another camera, described in U.S. Pat. No. 4,424,531, is equipped with cooling means and can be used in environments having extremely hot temperatures.
The constrained space camera assemblies of the prior art typically have a mirror or mirrors installed thereon so that the camera can view a wider range without movement of the camera. However, the prior art cameras suffer from serious limitations. Known prior art constrained space camera assemblies provide only monoscopic viewing and are ineffective in situations requiring enhanced stereoscopic imaging. Prior art cameras also have poor means of providing axial camera rotation. The assembly of U.S. Pat. No. 4,532,545, for example, is axially rotated by rotating the conduit which carries the assembly. Such a method imparts structural stress on the conduit and results in imprecise control over the assembly's radial orientation. Furthermore, many prior art constrained space cameras, such as that described in U.S. Pat. No. 4,532,545, have components that sometimes extend beyond the envelope defined by the assembly in the assembly's most compact configuration. If such a camera assembly fails while extended, then the assembly may be difficult to retrieve through the path in which it entered the viewing area.
Constrained space cameras are often used in environments having volatile and combustible gases. These gases can easily enter the camera assemblies in the prior art. A spark from electrical instrumentation within a camera assembly can ignite such gases to cause an explosion.
In view of the above, there is a need for an improved constrained space camera assembly which overcomes the above listed problems.